Fine needle aspiration (FNA) biopsy of palpable breast masses - Comparisonof conventional smears with the Cyto-Tek MonoPrep system

BACKGROUND: One of the limitations preventing the widespread use of fine-ne edle aspiration (FNA] is that it requires skill to obtain an adequate sampl e and well prepared smears. In this study, a new monolayer technique, the C yto-Tek MonoPrep MP) system, which obviates the need for smear preparation, was evaluated against conventional smear (CS) preparation for palpable bre ast lesions. METHODS: A total of 44 paired CS/MP breast FNA specimens were studied. The authors blindly analyzed the CS and the RIP slides separately, then by a si de-by-side evaluation. The two methods were compared with respect to diagno stic concordance, cellularity, cell preservation, background debris, and ti me needed to prepare and diagnose each case. RESULTS: An exact diagnostic correlation was present in 34 of 44 (77%) case s. The 10 noncorrelating cases were caused by decreased cellularity in the MP cases; nonetheless, 7 of these were correctly assigned to the right gene ral diagnostic category, whereas the remaining 3 cases had insufficient cel ls. In addition to overall lesser cellularity on MP, fibroadenoma cases had smaller epithelial sheets and absence of stroma compared with CS. Both met hods had comparable cellular preservation and diagnostic evaluation time, b ut background debris and preparation time were greater for MP. CONCLUSION: CS are favored over MP for the preparation of breast FNA specim ens in centers with specialized FNA services because of their higher diagno stic yield, ease of preparation, and availability for immediate cytologic e valuation. However, in settings where specimens are collected sporadically by unskilled clinicians, the MP system may prove to be useful as an alterna tive or an adjunct to CS. Cancer (Cancer Cytopathol) 1999;87:278-85. (C) 19 99 American Cancer Society.